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| Volume 1, Issue 01 - 2006, January |
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| 4 |
Synthesis of Unsaturated-Polyester/Organo-Clay Nanocomposites: A Fundamental Approach |
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| Pages 35-44 |
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| I. MIRONI-HARPAZ1, M. NARKIS1* AND A. SIEGMANN2 |
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| 1Department of Chemical Engineering;
2 Department of Materials Engineering,
Technion – Israel Institute of Technology, Haifa 32000, Israel |
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| Received 29 August 2005; accepted 1 November 2005 |
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| Unsaturated-polyester (UP) nanocomposites, based on UP-alkyd usually dissolved in styrene monomer, may be synthesized using numerous possible approaches. The conventional approach is the synthesis of styrene-containing UP-resin/organo-clay nanocomposites via a single-step procedure. Applying this approach the effects of various mixing processes, using several organically modified clay types, were investigated. Incorporation of these organo-clays resulted in an intercalated structure, the extent of which depended on the clays’ organic treatment. The second approach is the employment of a two-step procedure, in which the first step is the synthesis of styrene-free UP-alkyd/organo-clay nanocomposites. The effects of various mixing processes and several processing parameters were studied. Inducing high shear levels for prolonged time durations promoted the intercalation and exfoliation of the silicate layers, resulting in a better dispersion of clay particles. The high shear level effects were achieved by vigorous mechanical mixing and were intensified by using large amounts of clay and appropriate matrix viscosity. The UP-alkyd/organo-clay nanocomposites may be cured without styrene, using a new procedure recently developed in our laboratory, thus attaining thermoset UP-alkyd/organo-clay nanocomposites. The structure, thermal and dynamic mechanical properties of the thermoset nanocomposites were found to be highly affected by the peroxide content used. This methodological approach provides a basis for understanding the structuring processes involving the formation of the UP/clay nanocomposites and establishing materials-processing-structure interrelations. |
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